Alternator Switchout

[Madmiles442]

Disclaimer: My name is Miles and I am an electrical idiot. (group - "Hi Miles")

My alternator fried and I'm trying to install my 1-wire 100amp replacement. The old one is 4 wire, standard amp (65 I think). I'm adding pusher fans so I'm jumping up.
As is, looks like this.


I read a past thread where someone said to run the cable from the battery straight to the alternator, Remove the External Regulator and tape off the wires. Sounds easy enough, but my battery cable runs to this solenoid/relay (I wouldn't know the difference if one bit me). This is it coming up the right hand side.



From there, Big Red goes straight to the starter.
Out of the alternator, Brown, White and Black go into this Regulator. Red splits off prior to that into this plastic fastened bundle and disappears towards the front of the car into the fenderwell to who-knows-where.



What's the proper way to wire this up?
I sincerely appreciate any help you can offer.

[JRoss]

Hey Miles,

I can help you out, but its gonna cost you . Is the car drivable, can you get it to me? If not I should be able to get out to you some time this weekend. Give me a call this is easy to take care of.

John

[RedBarchetta]

Watching intently...

Miles, PM me. The guys from SCOF have a solution, but you're not going to like hearing it.

-Dean #747

[murray2658]

If it's not to much of a hassle could you share your insite with me on this? I to am ready to go to a 1 wire Alt. The previous owner did some funky things to the wiring and would love to bypass the headaches of figuring this out if there is a simple route!

Thanks!

[RedBarchetta]

In short (no pun intended), it's not the 100A alt install that's the problem. It's all the 50-60A wiring that is within the rest of the car, and without the proper breakers/fusable links, that could ultilmately lead to an electrical fire. If you want to live with the existing amp meter, you would need to 'spread' the load of the 100A being generated across a couple circuits. Or you could install a volt meter (which, from what I've learned, is more practical and valuable). But you still have to know what you're doing and how those extra amps will 'dance' through the existing wiring (or fry it).

Early SPF cars like the ones that Miles and I have will have wiring issues with an alt upgrade unless these things are considered. Newer SPF cars may be wired to accept a 100A alt...I'm sure a dealer could answer that one.

-Dean

[murray2658]

So in your opinion is it better just to replace the exsisting set up with new equipment? The alt in the car is not the original so I would just go back to the original set up and keep everyithing as is with out the possible barbacue!!

Thanks

[JRoss]

Ok, I dont know anything about superformance wiring being only able to handle 60a or the superformance amp meter but here is what I did on mine when I upgraded to a 140 amp alt.

Remove the field and stator wires completly. (They should only run between the alt and regulator.)

The other wire going to the requlator (usually white) is no longer use, tie it off.

The red wire going to the alt can still be used but it is only a 14 gauge and cannot support the load so you will need to add a 10 gauge jumper from the alt to the positive side of the starter relay. This will carry the majority of the load back to the battery and not thru the fuse box.

I have a Lone Star with a Painless Wiring kit and have been running this way for 7 or 8 years with no problems.

John

[Madmiles442]

Thank you for the feedback, guys.
One of the larger loads I'll have are my 15a each pusher fans (for looks only, yes I'm vain). So maybe it makes sense to isolate that as a load.
Blas has also told me the car doesn't have a main "breaker" and it would make sense to install one of those.
Solenoids, fusable links, relays, now a 10 ga jumper. Man, I'm out of my element.
I've ordered a complete wiring diagram for my car so I can make some progress.
I'll happily upgrade the gauge of wire necessary to avoid an electrical fire. I have this vision of a pop and then flames shooting out of my ampmeter....

[Blas]

The main power feed from the solenoid to the cabin of the car is a 4mm wire.
That wire feeds EVERYTHING electrical on the car.
Using US terms for reference:
6 ga is 4.11mm - so you have little less than 6 ga. wire feeding all your electrical services on your car.
6 ga wire is good for.~66-85 amps. (Remember: You ALMOST have A 6 ga wire feed) Others have done it successfully. The question is: "Are you feeling lucky"
Add the fuse or circuit breaker too. (80 amp)

Some Reference Info:

BOSCH Radiator fans 15A each: = 30A Total.
SPF supplied headlights high beams (60W/??W) = 5A each side/ ??A each side = 10A Total/ ??A Total.
Aftermarket Bulbs: 100W/130W = 8.33amps or 11A = 17A or 22A Total.
Brake Lights: (for halogen bulbs) = 4A ea side = 8A Total,
Std Tail lights: = 1A total.
MSD Ignition Module @ 5,000 RPM: = 5A Total.
Canton Accusump solenoid: = 1A Total.
Holly Red Fuel Pump: = 7.5A Total.
Hella Twin Supertone Horns: = 72W = 6A Total
Instrument Gauges: 7 Bulbs @ 2.2W each = 15.2W Total = 1A Total

[Madmiles442]

Hi Blas,
Are you talking about that little bitty red wire on the right side of the solenoid in photo #2 going into the firewall? Nah, really?
That thicker cable on the right comes from the battery and the thicker one on the left goes to the starter. That's the only thick ones I have. (yea, I know, that's what she said)

And, uh, no, I'm not feeling lucky at all. I've been bit too many times by electricity.
Sent you a check today for the wiring diagram.
Thanks again to all.

[Blas]

No, that may be your MSD Ignition power tap going thru the firewall..It's the other red wire going down from the solenoid, but on the same side as the MSD tap..

[Madmiles442]

Murray wanted to know how this came out, so here ya go.
3 wire 65a alternator to 1 wire 100a alternator.


Shiny new alternator in place. Used same bracket. New alternator came with a smaller wheel, so I had to go to a smaller belt. The voltage regulator is gone off the firewall too. The wires coming from it were dead-headed, except blue and blue/white, which were wired together. Don't know why, just what the wiring diagram tells me. The red ignition light near the key does not light any longer.



The single 6 ga cable coming from the new alternator goes to the hot side of the starter solenoid.



My year Superformance does not have fuse protection for the main wiring, so going up to 100amp would have fried the smaller gauge main wiring (possible fire). So I went to the local car stereo/Pimp My Ride shop and got an 80amp fuse. Installed it just downstream of the hot side of the starter solenoid. A good hidden accessible space for me was behind the glove box on the firewall.



Many many thanks to Blas, Dean and John for their input and help.
I really appreciate the help.